Clamping device



Sept. 1 1925..vv

G KRELL cLAMr-I'Ne DEVICE Filed Nov. 28, 1924 6... .v r '60 7 I PatentedSept. 1, 1925.

Gannon or 'saruLI-A, oxmnoma.

OLAMPING' DEVICE.

.- Application filed November 28, '1924. Serial No. 752,648.

To all when it comm: 4

Be itknown that I, Gronon KRELL, a citizen of Germany, residing atSapuIpa, in

the county of Greek and State of Oklahoma, have invented certain new anduseful Improvements in Clamping Devices; and I do declare the followingto be a full, clear,

and exact description of the invention, such as will enable othersskilled in the art, to which it appertains to make and use the same,reference being had to the accompanying drawings, and to the figures ofreference marlied thereon, which form a part of this specification.

This invention relates to clamping devices ,for pipe and the clampingmechanism has been especially designed for use in con-nection withevices used in the oil fields for drilling wells. For example, elevatorsfor casings, sucker rods and the like, spiders for the casing and thosedevices are commonly known as clamps. All-employ some form of jaw forgripping the pipe or sucker rod and in this respect there is an analogybetween all three, but the construction of the-supporting means or framefor the jaws in the elevator, the spider and the ordinaryv clampdiflers.

Therefore I would have it understood that in so Far as the genericapplication of the jaws and their operating means'is concerned, myinvention contem plates the inclusion of-such mechanism in any form ofclamp but specifically the supporting means illustrated inthe drawingsis adapted for a spider. Hence in the claims the word clamping device isintended to be generic to any for of clamp.

The novel construction 0 the preferred embodiment of my invention willbe clearly understood by reference to the following description inconnection with the accompanying drawings, in which Fig. 1 is aperspective view of a spider embodying my invention with the jaws inopen position.

Fig. 2 1s a vertical sectional view through the spider showing the jawsin clamping position.

Fig. 3 is a perspective view of a spider viewed from the side oppositeto that shown in Fig. 1.

Fig. 4: is a plan view of the spider, and F ig. 5 is a fragmentarysectional view through one of the slips.

The base frame 1 is shown as substan-' tially rectangular with a slot 2in one wall be inspected or re aired and .by means of which the framecan be moved into and out of position with respect to the pipe 3. Thesidewall '4 of the frame 1 is provided with a recess 5 to provideclearance for the toggle levers which operate-the aw member. Thesetoggle levers willbe described in detail hereinafter.

Theframe 1 carries two'sets 6 and 7 of upstanding bearing lugs, one setat each.

end. The lugs constitute bearings for the rock shafts 8 and 9 whichsupport the rocker arms 10, 11, 12 and 13 rigidly fastened to the rockshafts by set screws 14. The purpose of providing the set screws so thatthe rocker arms will be fast to the rock shafts is and '16 provided withtrunnions 17 and 18 mounted in the inner ends of the rocker arms.

The jaw members 15.and1 6 are pivoted in the rocker arm's below theirtransverse centers only so that the upper ends of-the jaw.

members will tend to spread apart, due to the fact that the center ofgravity of each aw member is above the transverse center of the awmember. ThlS 1s impossible where there are pivotal connections for thejaws 15- I above-the transverse centers. The purpose of .so mounting thejaw member is to cause the lowermost teeth 19. and 200i the slips 21 and22 to firmly grip the article clamp'd,"-

for example the pipe 3. Therefore if-the lower teeth become worn, thenext s'ucceeding teeth will be sharp enough to 'I'obtain the .nccessarygrip on'the pipe. Theslips 21 and 22 are shown as provided withtransform of segments. They are removably fastened to the jawmembers'i15 and 16' by bolts 24am]- 25, -The slips are removable for twopurposes, first so that the sli s can cause slips having aces-cutondiflierntarcs can be introduced in the same jaws fbntaking care ofvarious sizes-ofpipe..'

The ends of the aw members. an'd16 verse teeth 19 and 20, the slipsbeingin the 9 are beveled or flared outwardly 'as indicated at 26, 27,'28 and 29,*sothat theends of. the pipe will be properlyguided'betweenthe jaws. The inner walls of the slipsvin' the jaw members'are alsobeveled as at 30 and 31, to permit the coupling on pipe 3 to passthrough the jaws as the pipe is being removed. The jaws aremaintainedfin subbeing desirable that the jaws firmly eng of clamp,

stantially effective parallelism by the rod 33 which passes through theear 34 on jaw 15 and through the rear 35 on jaw 16, it age the pipe 3 tohold it suspended in the well, and since the teeth 19 and 20 for theslips 21 and 22 are arranged in horizontal planes, it will be ap arentthat tendency of the pipe to slip ong'rtudinally will be eliminated.These teeth under all conditions will not be effective in preventingturnin of the pi e about its axis so the pipe will ave a ten ency toslip when a wrench is used to connect or disconnect the pipe sections.In order to overcome the tendency of' the pipe rods or the like to turnabout its axis, I provide dies or inserts 36 and 36' which are providedwith vertical or longitudinal teeth 37, the teeth of the insertprojecting inwardly sli htly beyond the teeth 19 so that they wil gripthe article to be clamped in a manner firm enough to prevent the articlefrom turning about its axis. This is quite an important feature inany'form particularly those used in the oil fields. The main purpose ofinsetting I the teeth 37 with respect to the teeth 19 is as comprising alever 38 that, when the jaws take hold of the pipe, the teeth 37 willsink intJo the pipe just enough in excess of the teeth 19 to hold theagainst turnin when a wrench is applied to the next'lughest pipesection. If both sets of teeth were coincident at their outer edges anda wrench was used to turn the next highest pi e section, the teeth 37would tend to 1111 ofi or at least fail to hold as efiicientl y as withthe arrangement described.

Inasmuch as the'jaws 15 and 16 have considerable weight, it is essentialthat some form of jaw openingmechanism be provided which may beconveniently operated with little power to spread the jaws apart,itbeing understood that the jaws always have a tendency to swing intoclamping position due to the fact that they are supported above the rockshafts 8 and 9.

The jaw opening mechanism is illustrated pivoted to a lug 39 on theframe 1, the lug 39 having a stop projection 39' for the lever 38.Movable longitudinally in the uide lugs 40 and 40 on the lever 38 is aog 42 which is nor mally urged into engagement with a recess 41 in lug39 by an expansion spring 42', one end of which bears against lug 40 andthe other against the pin 44. The dog can be moved out of engagementwith any one of the openings 41 by a hand lever 45 pivoted to the lever38 at 45 and connected to the dog by a link v46.

The lever 38 is fast to a rocking stub shaft 47 in the lug 39, the innerend of the rocking stub shaft carrying an arm .48 which is pivoted tothe two toggle levers 50 and 51- in eagues turn connected to thetrunnions of the jaw members 15 and 16. The inner ends of these leversmay be received in the recess 5 when the jaws are in clamping position,the recess 5 being merely a clearance for the ends of the levers. Itwill be impossible to operate the lever 38 in such a manner that thepivotal connection 52 will be above a horizontal plane passin throughthe trunnions, because before t at can occur, the lug 40 will contactwith the stop 39". Therefore the jaws will always have a ten dency toseat themselves or drop into pipe or rod clamping position. When lever38 is swung in either direction, shaft 47 rocks swinging arm 48 fast toit. The arm 48 imparts movements to the to 'gle links 50 and 51 which inturn rock liifirs 10,-11, 12 and 13 fast to the rock shafts 8 and 9 sothat the shafts 8 and 9 rock in their re spective bearings.

Since one side of with a slit or slot 2, that side of the casting isbraced by a tie rod or brace rod 54 connected to the rock shafts 8 and9. The ends of the frame 1 are provided with outstanding projections 55and 56 which carry links 57 and 58 whereby the frame may be connectedtoa hoist to move it into and out of functional position. provided withdepending lugs 60, one at each corner, each lug being provided with aset screw 61, by means of which the frame may be fastened to a supportwhere the clamp is incorporated in a spider.

In actual practice I prefer to have the links 10, 11, 12 and 13 on anles of. about 65 from the horizontal, as I nd that this angle ofinclination for the links,insures an adequate gripping surface for thejaws and any lesser angle seems to lessen the gripping efliciency of thejaws. -Obviously however, I do not wish to be limited to this particularangle.

When the parts are assembled and it is desired to use the invention as aspider, the frame maybe clamped to its support, for examplefto thecasing head 62. Then the pipe is lowered by theelevator 'to the desireddepth, the spread jaws are adapted to seat themselves against the pipeand swing down to seating position to hold the pipe while a new sectionof pipe or casing is screwed on as is Well understood, then the lever 38will be operated to spread the jaws apart so that the pipe may belowered a sufficient distance to allow a new section of pipe to bescrewed on and so on until the desired length of string of pipe isprovided. The position of the pivot point 52 is important because I havefound that by pivoting the toggle lovers 50 and 51 and the arm 48 at apoint coinciding with the plane passing through the axis of the openingin the frame that the jaws can be opened with relatively little Theframe is also the frame is provided February 27,

' of ,the bolts they can slips is that the bolts pass are below thelongitudinal center the center of the frame.

other words power and that each jaw will tend to move substantially thesame distance away from Thus the jaws can be opened with grcaterfacilitythan if the arm 48 was pivoted to one of the links 50 and 51 to one sideof the center line of the frame.

When it is desired to remove the spider the bar 54 may be removed, thenthe spider can be slipped to one sidebecause the slot 2 is wide enoughto permit the largest sized pipe to pass through it.

In m former Patent #1,446,568, dated 1923 for an elevator, I have showna certain form of jaw mechanism which has certain advantages in anelevator but since filing the application for that patent, I havedeveloped the improvements in jaw mechanism enumerated in thisapplication and I find by actual practice that the same form of jawmechanism illustrated in this application and the same form of jawspreading mechanism illustrated in this application is better adaptedfor the elevator than the mechanism shown in said patent. Therefore Irecommend the jaw mechanism shown in this application and the jawspreader shown in this application as a better form to be used inconnection with an elevator. Practical experience has shown that if thefastening devices used for securing the slips in the aws are insertablefrom the inner sides of the jaws and slips and do not pass through thejaws, difficulty is encountered in removing the fastening devicesavhenthe slips are to be changed. This is due to the fact that salt watercauses corrosion about the fastenin devices so that they freeze.Therefore I ma e the bolts 24 and 25 long enough to passthrough theslips and through the jaw me bers' and hold them by nuts 24 and 25. Thisallows the fastening devices to be manipulated from the outside when itis desired to take out the slips. In

the nuts 24: and 25 can be reon the threaded ends e loosened as the saltwater does not affect the outside nuts. Even if it should the nutsaremore accessible than the inner ends of the bolts. 7

Another feature in connection with the holes through which the moved andby tappin of the slips and of the jaws. The main purpose of thisconstruction'is to prevent the slips getting in upside down. thearrangement shown it will be impossible to put the slips inincorrectlybecause the holes in .the slips must match withthe holes inthe jaw members.

Attention'is also'calle'd to the fact that there is a marked advantagein havingthe top end of the jaws swung outwardly when the pipe is-aboutto be engaged by the jaws. The advantage is this ;v the lower teeth ofthe central opening in the slips first take hold and then the remainingteeth. Therefore the lowermost teeth take the shock and as they wearaway the next higher teeth, still sharp, take the shock so that theteeth of the slips wear away progressively from the bottoms. of the jawsto the tops instead of all the teeth wear ing away simultaneouslyfAccording to my invention then there will always be sharp teeth on theslips until they have all worn off iprogressively from the bottom endsupward. I

The location of the lever 38 with the arm 48 for operating the jaws isan important part of this invention, because the aws 15 and 16 are quiteheavy so that the leverage ratio must be considerable tospread themapart Therefore by locating ,the pivot point of the lever 38 between theshafts 8 and 9, the necessary leverage can be'obtained for opening thejaws.

Where the lever is mounted in actual alignment with one of the rockshafts 8 or 9 or outside the rock shafts 8 or 9, an excessively longlever 38 is necessary so long indeed as to make the inclusion of a leveralmost rohibitory. Particularly is this true w ere the mechanism is usedin connection with an elevator, for it should be borne in mind thatattention must be aid toclose clear'- 3 ances for the walking beam andthe like i when the tubing is being pulled.

Inasmuch as different (hametersof pi" are used it is desirable to havethe slips and 22 removable. A set of sli s cani-hp'; made to be used ina single set 0 jaws for varying diameters of pipe. sist of a number ofpairs of slips, all the pairs having the same are or curve oil-theirouter faces but the inner faces of each pair will differ as to are orcurve, the are being that which will best suffice' for a articulardiameter of pipe. Therefore if t e device is used for a 10-inch pipe andit is desirable to operate on 8-inch'or 6-inch pipe, it will; onlynecessary to remove the 10-inch slipsa substitute the 8-inch or 6-inchslipsjnd course this also ap lies to slips or other... diameters ofpipe. he substitution dfthe 1- interchangeable slips for those alreadyin thejaws can be quickly and expeditiously made by taking out the bolts24: and 251th;- moving the slipsand substituting other Y It will beobserved that the jaws are pro- 1 9 vided with recesses receive theslips so thatwhen the nuts on the bolts 24 and 25 are tightened, theslips will be securely held I in place, the edges of the recessesin" theaws supporting the weight. 1

Attention is also called to the fact that the. base or frame 1 is ofless diameter than the spac between the jaws when the jaws are opened,thus the central opening for thepipe 2: will eon 1 stitute a guidg forguiding the pipe intoproper positidrgto be embraded the jaws. What I clam and desire to secure by Letters-Patent is 9- 1, A clamping devicecomprising a sup- 7 port, rocking aw-c'arrying'members on the support,andjcomplementary jaws carried by the rockmgmembers, movable one towardthe other forblampin an object between them, the jaws being jplvoted tothe rocking members below their transverse centers only,

so that the upper-ends of the complementary jaws will tendto spreadapart.

"2. A clamping device comprising asapp0rt,rockin jawcarrying memberson'the support an complementary jawscarried by the rocl rfing members,movable one toward the other for clamping an object between them, thejaws being pivoted to the rocking being effective in spreading them.

members below their transverse centers only, so that the upper ends ofthe complementary jaws will tend to spread apart, and means forspreading said jaws. V

3. A clamping device comprising a support, rocking jaw-carrying memberson the support, complementary jaws carried by the rocking members,movable one toward the other for clamping an object between them, thejaws being pivoted below their trans verse centers only, so that theupper ends of the complementary jaws will tend to spread apart, andmeans for opposing the tendency of the jaws to move together, said means4. A clamping device comprising a frame, rocking aw-carrying members onthe frame, and two diametrically opposite complementary clamping jawscarried by the rocking members, the jaws being pivoted below theirtransverse centers only, so that the upper ends of the complementaryjaws tend to spread apart, and means for spreading said aws.

5. A clamping device comprising a frame, rocking j aw-carrying memberson the frame, two diametrically opposite clamping jaws carried by therocking members, the jaws being pivoted below their transverse centersonly, so that the upper ends of the complementary jaws tend to spreadapart, means for operating said jaws and means carried by the jaws toprevent the article clamped from turning with respect to the jaws, saidmeans comprising lateral teeth and longi tudinal teeth. one 'set ofteeth extending inwardly slightly beyond the other set of teeth. (5. Aclamping device comprising aframe, two diametrically opposite clampingjaws carried by the frame, the jaws being pivoted below their transversecenters only so that the upper ends of the complementary jaws withrespect to the jaws, said means comends of the prising lateral teeth andlongitudinal teeth, one set of teeth extending inwardly slightly beyondthe other set of teeth. i

7. A clampin device comprising a frame, two diametrica ly oppositecomplementary clamping jaws carried by the frame, the j aws beingpivoted below their transverse centers only so that the upper ends ofthe comple mcntary jaws will tend to spread apart, means for operatingsaid jaws and means carried by the jaws to prevent the article clampedfrom turning with respect to the jaws, said means comprising lateral.teeth and longitudinal teeth, the longitudinal teethextending inwardlyslightly. beyond the other set of teeth.

8. A clamping device comprising a frame, rocking jaw-carrying members onthe frame, two diametrically opposite complementary clamping jawscarried by the rocking members, the jaws being pivoted below theirtransverse centers only, so that the upper complementary jaws will tendto spread apart and means for operating said jaws, the jaws havingoutwardly beveled top and bottom edges.

9. A clamping device comprising a frame, rocking jaw-carrying members onthe frame, two diametrically opposite complementary clamping jawscarried by the rocking membcl's, the jaws being pivoted below theirtransverse centers only, so that the upper ends of the complementaryjaws will tend to spread apart, meansfor operating said" jaws, lugs onthe frame and adjustable fastoning devices in the lugs to rigidly securethe clamping device to a support.

10. A clamping device comprising a frame, parallel rock shafts carriedby the frame, complementary clamping jaws having supports rigidlysecured to the rock shafts, the jaws being movable toward and away onefrom the other and means for spreading said jaws apart. v

11. A clamping devicecomprising a frame, two parallel rock shaftscarried by the frame, jaws having supports rigidly mounted on the rockshafts and having swinging movement toward and awayfrom the center ofthe frame, the ends of the jaws being beveled outwardly, means in thejaws for preventing the article clamped from turn.- ing, said meanscomprising lateral teeth and longitudinal teeth, one set of teethextending inwardl slightl beyond the other set of teeth an means forspreading the jaws.

12. A clamping device comprising a frame, two parallel rock shaftscarried by the frame, jaws having supports rigidly mounted on the rockshafts and having swinging movement toward and awa from the center ofthe frame, the ends 0 the jaws being beveled outwardly, means in thejaws for preventing the pipe from turning, said means comprising lateralteeth and longitudinal teeth, one set of teeth extending inwardlyslightly beyond the other set of teeth, means for spreading the jaws,and securing means carried by'the respective corners of the frame.

13. i A clamping device comprising a frame, two parallel rock shaft-scarried by the frame, jaws having supports rigidly mounted on the rockshafts and having swi igi ing.-

movement toward and away from the center of the frame, the ends of the.aws being beveled outwardly, means in'the ]i1WS'l'Ol reventin thearticle clam ed from turning, said means comprising lateral teeth andlongitudinal teeth, one set of teeth extending inwardly slightly beyondthe other set of teeth, means for spreading the jaws, and clampingdevice securing means carried by the respective corners of the frame,said means comprising set screws.

14. A clamping device comprising a frame, complementary jaws carried bythe frame. the jaws being pivoted below their transverse centers, apairof toggle. levers connected one to the otherand at their ends to thejaws, and an operating lever pivoted to the frame and connected to the,toggle levers slightly to one side of a plane pass-- ing through theaxis of the opening described by the aws when the aws are inclampingposition.

15. A slip for removable attachment to a recessed clamp jaw of an oilwell casing spider and the like, comprising a substantially rectangularbody having transverseteeth, and a removable insert having verticalteeth, the vertical teeth of the insert extend in g slightly beyond thehorizontal teeth.

16. A slip for removable attachment to a recessed clamp jaw of an oilwell casing spider and the like, comprising a substantially rectangularbody having transverse teeth, and a removable insert having verticalteeth. the vertical teeth of the insert extending slightly beyond thehorizontal teeth, the insert being receivable in the upper edge of thebody.

17. A slip for removable attachment to av recessed clamp jaw of an oilwell casing spider and the like. comprising asubstantially rectangularbody having transverse teeth. and a removable'insert having verticalteeth, the vertical teeth of the insert extending slightly beyond thehorizontal. teeth. the insert being receivable in'the upper edge of thebody, the slip having an offset opening below its transverse center toreceive a bolt passing through the jaw so that when the offset openingin the slip cw incides with the bolt the insert must be at the top ofthe slip.

18. A slip for'rernovable attachment to a recessed clamp jaw of an oilwell casing spider and the like. comprising two members, one a main bodymember and the other an insert therefor, one of the members havinghorizontal teeth and the other vertical teeth, the teeth of one memberproject.- i ng slightly beyond the teeth of the other.

19. A clampingdevice, comprising-a1 support, jaw carrying rocker armspivoted to j the support, complementary jaws pivoted to the: rocker armsbelow their transverse centers only, jaw operating means comprising alever pivoted tothe support between the pivots ol the rocker arms, andoperating connections between the lever and the jaws.

20A clamping device comprising a sup.

port, shafts at opposite ends of the support,

rocker arms on the shafts, jaws carried by the rocker arms, the jawsbeing pivoted to the rocker arms below their transverse centers only,jaw operating means comprising links connccted one to the other and tothe complementary jaws. and a lever connected to the links, the leverbeing mounted be tween the shafts. 1

21. A slip for removable attachment to a recessed clamp jaw of an oilwell casing spider and the like, comprising two memhers. one a main bodymember and the other an insert therefor, horizontal teeth on the mainbody member and vertical teeth on the insert, the vertical teethextending inwardly, slightly beyond the horizontal teeth of the mainbody n'iember.

A clamping device comprising a supporthaving rocking members,complementary jaws, movable one toward the other for clamping an objectbetween them, the jaws being pivoted to tlnrroclting members below theirtransverse centers only, and to one side ol :1 vertical plane passingthrough the jaws so that the upper ends of the jaws will tend to spreadapart. 23. clamping device r-oniprisir a support having rocking members.CfUlIlPlBDNl'P' tary jaws, movable onetoward the other for clamping anobject between them, the jaws being pivoted to the rocking members belowtheir transverse centers only. and to one side of a vcrtical planepassing through the aws aws being pivoted to the rocking members Intestimony whereof I afiix my signature. I

GEORGE KRELL.

